I used that method already. but there's huge drawback, if you refresh the window, the variable is gone and if the have the code like myWindow.focus(); you will get an error. and in my situation, it's not allowed.
That is the reason I am looking for other alternative way...
@AdamGundryJun 30.2004 — #I believe (see [url=http://home.online.no/~warnckew/programming/remote/window.html]this article[/url]) that you can do this to get the window handle again:
var myWindow = window.open('', '[i]WindowName[/i]');